The present invention relates generally to an air break disconnect switch for high voltage electrical applications and, more particularly, to a communication system controlled motorized in-line high voltage air break disconnect switch that mounts in-line with the transmission line conductor without the need of a group operated switch with associated ground supported mounting structure. Such a communication system controlled motorized in-line high voltage disconnect switch hangs from and is supported by its associated transmission line. In particular, the present invention is directed to a novel system for locking out such a switch for safety reasons.
One example of a non-communication system controlled non-motorized in-line high voltage disconnect switch is a vertical break disconnect switch currently manufactured and sold by Cleaveland/Price Inc., of Trafford, Pa., the present Assignee, as a type ILO-C, Hookstick Operated In-Line Transmission Switch. The switch is described in Cleaveland/Price Bulletin DB-1021611, entitled “Type ILO-C Hookstick Operated In-Line Transmission Switch 69 kV-230 kV 1200 A.”. The switch is rated 69 kV-230 kV, 1200 amperes. The Cleaveland/Price Inc. type ILO-C In-Line high voltage disconnect switch utilizes a manually operated hookstick for engaging an operating eye ring attached to the breakjaw end of the switch blade of the switch. The hookstick when engaged with the operating eye ring imparts rotation to the hinge end of the switch blade for opening and closing of the switch. The Cleaveland/Price Inc. type ILO-C In-Line high voltage disconnect switch is a single phase switch and is versatile and can serve many functions on a three phase system. The switch can be used to sectionalize long transmission lines, disconnect lines from substations, serve as a line tap switch, and serve as a temporary maintenance switch, for example. The Cleaveland/Price Inc. type ILO-C In-Line high voltage disconnect switch saves significant installation costs compared to a non-in-line switch installed via direct ground support mounting structure. The Cleaveland/Price Inc. type ILO-C high voltage disconnect switch allows for easy, cost efficient sectionalizing of high voltage transmission lines and isolation in high voltage substations. As a result of this, the type ILO-C In-Line high voltage disconnect switch has been used by electric utilities for many years to isolate transmission and substation circuits.
U.S. Pat. No. 9,881,755 B1 by Charles M. Cleaveland and issued to Cleaveland/Price Inc., the present assignee, on Jan. 30, 2018, discloses a communication system controlled in-line motorized high voltage disconnect switch. The switch includes an elongated strain insulator supporting an elongated rotating switch blade having a hinge contact end and a break jaw contact end. The rotating switch blade is rotatable about a hinge pin at the hinge contact end during opening and closing of the switch. The switch includes a motor connected to an output shaft to cause the hinge end of the switch blade to rotate when energized to open or close the switch. A communication system actuates the motor to cause the switch to open and close as desired. The communication system may include a number of communication devices. The Cleaveland/Price Inc. patent discloses embodiments of a vertical break and a side break in-line motorized high voltage disconnect switch. Both the vertical break and side break switches include an elongated switch blade that is rotatable at one end of the switch blade, i.e., about the hinge end.
Reference is also made to U.S. Pat. No. 9,966,207 B1 by Charles M. Cleaveland and issued to Cleaveland/Price Inc., the present assignee, on May 8, 2018, which also discloses a Motorized High Voltage In-Line Disconnect Switch With Hand-Held Communication System To Prevent Unwanted Operation. The switch includes a rotating switch blade that is operated by a communication system controlled motor that may include a switch mounted communication device, such as a radio which is controlled by another such communication device located in a hand-held portable controller that is battery powered to provide a secure way to open and close the switch without traditional padlockable manual operators that are vulnerable to terrorist attack. The switch is battery operated and solar charged.
Another such communication system controlled in-line motorized high voltage disconnect switch is disclosed in U.S. patent application Ser. No. 16/271,795 filed Feb. 9, 2019, by Peter M. Kowalik and James R. Shychuck, and assigned to the present Assignee, Cleaveland/Price Inc., and entitled “In-Line Motorized Double Break Disconnect Switch”. This invention discloses a high voltage motor operated in-line double break disconnect switch suspended by an electric power line conductor wherein the switch includes a horizontally rotating switch blade, that is suspended by a motor output shaft attached to the midpoint of the blade of the switch blade to balance the blade. A communication system is disclosed for controlling the motor that may include a switch mounted communication device such as a radio which may be controlled by another such communication device located at a distance and powered by a solar charged battery or alternatively controlled by a hand-held controller.
The said U.S. Pat. No. 9,881,755 B1 and U.S. Pat. No. 9,966,207 B1 and U.S. patent application Ser. No. 16/271,795 are each incorporated herein by reference in their entireties as though fully set forth.
Padlocks are commonly used by utilities on high voltage air break disconnect switches as lock out devices. They are used to prevent high-voltage disconnect switches from being opened or closed. These disconnect switches are generally located in a substation or equivalent area and may have either manual operation through swing handles or handcrank gearboxes or may have remote operation through motor operators. The lock out devices, such as padlocks, are purely mechanical in nature. They may use mechanical locks with plungers that prevent motion of the switches when the plunger is extended. Such locks are operated by a special key that can only be removed from another lock when that lock is in correct position to release the key. There are also mechanical locks that slide and release a vertical operating pipe of one switch while locking the vertical operating pipe of another associated switch. This allows one switch to operate only while the second switch is in a particular position. As can be seen, lock out locks and interlocks are critical to the safe operation of many of the disconnect switches on an electric utility system. While doing maintenance on the transmission line switches are locked open using a padlock on a vertical operating pipe to provide safety for working personnel.
The above-referenced communication system controlled in-line motorized high voltage disconnect switches as disclosed in the said U.S. Pat. No. 9,881,755 B1 and the said U.S. Pat. No. 9,966,207 B1 and U.S. patent application Ser. No. 16/271,795 all hang on a utility's power line, i.e., in-line, and have no connection with the ground below to allow for lock out operation. These new versions of disconnect switches are battery powered and are commanded to operate by radio/remote control, either from a supervisory control and data acquisition (SCADA) communication system or a hand held transmitter in close proximity to the switch. This type of switch has many advantages over the prior art style of switch that needs an area of ground, foundations, supporting structures, fences, padlocks for lockout and is accessible to terrorists or other malcontents. These new versions of disconnect switches are commanded by secure encrypted radio signals and require a bucket truck to physically reach them.
One issue that both the above-referenced communication system controlled in-line motorized high voltage disconnect switches and the prior art style of switch have in common is the need to be locked out to prevent accidental or unintended operation. Utilities using the new versions, i.e., communication system controlled in-line motorized high voltage disconnect switches will not necessarily want to travel to the switch location in a bucket truck to lock out the switch using a hot stick to engage a locking device. It is therefore an object of the present invention to provide a lock out system that can securely lock out the switch blade of the switch from movement, especially one that prevents an open switch from closing, and that can be operated by remote control. This is critical to the safe use of the new versions of switch. It is a further object of the present invention to provide a manual operation aspect of the lock out system in the event an onboard battery for powering a lock out motor has failed or other unforeseen issues cause a failure of the switch or the remote control feature of the lock out to operate.